North eastern Laos is rugged, mountainous, remote and a bit tricky to navigate – until a few years ago, parts of it had no proper road links with the rest of the country and a couple of provinces were still not entirely safe due to anti-governement insurgency by Hmong guerillas. Also, it’s littered with unexploded bombs, so in recent years it hasn’t really attracted the visitors in droves. The roads are there now though, just about, and the guerillas are gone, and the bombs aren’t under any footpaths, so we’ve been able to spend the past week or so in this gorgeous, peaceful area – an absolute bugger to get to but well worth the effort.

The first stop was Phonsovan, which we reached from Nong Khiaw in a mere eight hours thanks to a juggernaut of a bus that rattled like a toolbox but was big enough to scare everything else off the road. Phonsovan is a quiet little provincial town that attracts a modest crowd of visitors for two main reasons – old jars and old bombs. We saw lots of both.

The Plain of Jars is a series of archeological sites surrounding Phonsovan that have had boffins scratching their heads for ages. Each site is dotted with hundreds of huge stone jars, but nobody can figure out what they were used for – burial urns, primitive brewing devices and cooking vats are a few of the more sensible theories but, due to the absence of any organic evidence like bones or food, they haven’t even been dated accurately, let alone neatly categorized and explained by a team of smug looking museum geeks. We took a sweaty cycle ride to the largest site, an eerily quiet expanse of grass scattered with about 300 jars, and had a picnic while staring down the hill, trying to imagine what on earth would possess anyone to go to the trouble of building so many massive squat toilets in one area. Perhaps the chillis were hotter in those days. The plain itself was disconcertingly atmospheric and scarred here and there with enormous craters…which brings me on to Phonsovan’s second dubious claim to fame – the bombs.

In 1964, when the United States government escalated the war in Vietnam by ordering covert bombing missions to target Lao and Cambodian territory, the Plain of Jars was a primary strategic target. Between 1964 and 1973 the US air force conducted more than half a million missions over Laos, depositing 200 million tons’ worth of ordinance, one third of which failed to detonate. In consequence, the Plain of Jars and the surrounding countryside – most of which is owned by subsistence farmers – is littered with unexoploded ordinance (UXO), which is estimated to have killed more than 30,000 people since the end of the war in 1973, one third of them children (who often collect scrap war metal for cash).

Apart from the craters, Phonsovan and the surrounds are decorated by countless material reminders of the war – rifle cartridge key rings, missile shell flower boxes, tools bashed out of discarded helmets, even houses are supported by old artillery shells. We visited the local office of the Mines Advisory Group, a Manchester based NGO which undertakes UXO clearance work here, and learned more stats than you would ever care to know about this ongoing legacy. For example: from 1964 to 1973, more ordinance fell on Laos than fell in Europe during the entirety of the second World War. MAG estimates that at current rate of clearance it will take roughly 100 years to make the area safe.

With those stats ringing in our ears we took the (worst) bus (in Asia) from Phonsovan to Sam Neua – only 200km as the crow flies, but it took nearly 9 hours to chug and heave our way through the mountains, averaging a speed of 20km per hour up the steep uphill sections and ramping up to a heady 35km per hour on the rare downhill stretches. The road was a sinuous, narrow tarmac strip just wide enough for two vehicles to pass or overtake, hugging the edge of steep hilltops on one side and shaded by swathes of giant fern and bamboo on the other – gorgeous, and a bit scary.

From there, after a night’s recovery, we took yet another bus to nearby Vieng Xai, a peaceful, sleepy little town with a revolutionary history. The town is surrounded by dozens of deep limestone caves which used to be the secret city of the Pathet Lao, the communist revolutionaries who fought a civil war on the ground against the US backed Royal Lao Army while the US airforce bombarded them from the sky. From the beginning fo the secret war in 1964, Vieng Xai became the epicentre of political and military resitance and, in 1973, was briefly hailed as the capital of the liberated zone until the victorious Pathet Lao (whose politial arm still runs the country today) were able to move into Vientiane. The caves themselves have barely been touched since the Polit Bureau members moved out: they are unbelievably eerie, especially the sealed rooms containing massive Soviet oxygen machines in case of a gas attack, and the more homely touches include a bust of Lenin and a portrait of Che Guevara – essential decor for communists and students the world over. Wandering round the meeting rooms, kitchens, offices and gas chambers while the rain hammered down outside was not an experience I’ll forget in a hurry.